Coronary artery disease may cause the blood vessels providing blood to the heart to develop lesions, such as a stenosis (abnormal narrowing of a blood vessel). As a result, blood flow to the heart may be restricted. A patient suffering from coronary artery disease may experience chest pain, referred to as chronic stable angina during physical exertion or unstable angina when the patient is at rest. A more severe manifestation of disease may lead to myocardial infarction, or heart attack.
A need exists to provide more accurate data relating to coronary lesions, e.g., size, shape, location, functional significance (e.g., whether the lesion impacts blood flow), etc. Patients suffering from chest pain and/or exhibiting symptoms of coronary artery disease may be subjected to one or more tests that may provide some indirect evidence relating to coronary lesions. For example, noninvasive tests may include electrocardiograms, biomarker evaluation from blood tests, treadmill tests, echocardiography, single positron emission computed tomography (SPECT), and positron emission tomography (PET). These noninvasive tests, however, typically do not provide a direct assessment of coronary lesions or assess blood flow rates. The noninvasive tests may provide indirect evidence of coronary lesions by looking for changes in electrical activity of the heart (e.g., using electrocardiography (ECG)), motion of the myocardium (e.g., using stress echocardiography), perfusion of the myocardium (e.g., using PET or SPECT), or metabolic changes (e.g., using biomarkers).
For example, anatomic data may be obtained noninvasively using coronary computed tomographic angiography (CCTA). CCTA may be used for imaging of patients with chest pain and involves using computed tomography (CT) technology to image the heart and the coronary arteries following an intravenous infusion of a contrast agent. However, obtaining anatomic data using CCTA often means that models based on the anatomic data reflect a patient's state as he/she is undergoing imaging (e.g., CCTA imaging). Therefore, anatomic models for assessing blood flow rates are based on patient conditions during an imaging procedure. For example, patient-specific anatomic models for simulating arterial blood flow are often obtained while a patient is in a baseline condition during imaging and prior to treatment. However, various forms of treatment may affect anatomy and consequently, blood flow.
In other words, a patent's state may change due to any array of medical procedures and/or health conditions. Meanwhile, models for assessing blood flow may fail to reflect the change in state. As a result, there is a need for methods and systems accounting for changes in a patient's physiological state in indirect assessments of blood flow rates. In particular, there is a need for methods and systems for creating an anatomical model based on a patient's change in state in order to improve the accuracy of a simulation performed using the model. More specifically, creating an anatomical model may entail modeling changes in patient-specific blood vessel geometry and boundary conditions.
The foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.